Distance measuring device having light receiving areas of different sizes

• US 5,457,525 A
• Filed: 07/19/1994
• Issued: 10/10/1995
• Est. Priority Date: 01/16/1992
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ohtsuka, Masanori, Tsunemiya, Takanobu
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US08/277,135
• Time in Patent Office: 448 Days
• Field of Search: 250/206.1, 356/1, 356/3.06, 354/403
• US Class Current: 356/3.06
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 7/481 Constructional features, e.g. arrangements of optical elements

Abstract

A distance measuring device is arranged to emit spot-shaped light toward a subject and receive light reflected from the subject by means of a light receiving sensor having a plurality of light receiving areas, thereby measuring the distance to the subject. In the distance measuring device, among the plurality of light receiving areas, a peripheral light receiving area is selected to be larger than a central light receiving area so that the accuracy of distance measurement is improved.

Claims

1. A distance measuring device comprising:

light emitting means including a plurality of light emitting portions; and

light receiving means having a plurality of light receiving areas respectively corresponding to said plurality of light emitting portions, for receiving light emitted by said light emitting means and reflected from a subject;

wherein, among the plurality of light receiving areas, a plurality of peripheral light receiving areas has larger areas than a light receiving area substantially centrally positioned with respect to the plurality of peripheral light receiving areas.

2. A distance measuring device according to claim 1, wherein the plurality of light receiving areas respectively have dimensions measured with respect to a predetermined direction and the dimension of a peripheral light receiving area in the predetermined direction is larger than the dimension of a central light receiving area in the predetermined direction.

3. A distance measuring device according to claim 1, wherein said plurality of light receiving areas are respective position sensors.

4. A distance measuring device according to claim 2, wherein the predetermined direction substantially coincides with the length-wise direction of the plurality of light receiving areas and wherein the measured dimensions are lengths of respective light receiving areas.

5. A distance measuring device according to claim 2, wherein the predetermined direction substantially coincides with the width-wise direction of the plurality of light receiving areas and wherein the measured dimensions are widths of respective light receiving areas.

6. A distance measuring device comprising:

light emitting means; and

light receiving means for receiving light emitted by said light emitting means and reflected from an object, said light receiving means having a plurality of light receiving areas arranged in a predetermined direction,

wherein, among the plurality of light receiving areas, a plurality of peripheral light receiving areas has greater widths, as measured in a direction other than the predetermined direction, than a light receiving area substantially centrally positioned with respect to the plurality of peripheral light receiving areas.

7. A distance measuring device according to claim 6, wherein said light emitting means comprises a plurality of light emitting parts and said light receiving means comprises a plurality of light receiving sensors respectively corresponding to said plurality of light emitting parts.

8. A distance measuring device comprising:

light emitting means comprising a plurality of light emitting parts; and

light receiving means for receiving light emitted by said light emitting means and reflected from an object, said light receiving means having a plurality of light receiving sensors arranged in a predetermined direction, said plurality of light receiving sensors respectively corresponding to said plurality of light emitting parts,

wherein, among the plurality of light receiving sensors, a plurality of peripheral light receiving sensors has greater lengths, is measured in the predetermined direction, than a light receiving sensor substantially centrally positioned with respect to the plurality of peripheral light receiving sensors.

9. A distance measuring device comprising:

light emitting means having a plurality of light emitting parts; and

light receiving means for receiving light emitted by said light emitting means and reflected from an object, said light receiving means having a plurality of light receiving areas respectively corresponding to said plurality of light emitting parts, and said plurality of light receiving areas including a marginal light receiving area and a central light receiving area, said marginal light receiving area being larger than said central light receiving area.